[PATCH v10 05/27] drm/xe: Add EUDEBUG_ENABLE exec queue property

[Mika Kuoppala <mika.kuoppala@linux.intel.com>]

From: Dominik Grzegorzek <dominik.grzegorzek@intel.com>

Introduce an immutable eudebug property for exec_queues,
using a flags value to enable eudebug-specific features. For now, the
engine LRC uses this flag to enable the runalone hardware feature.
Runalone ensures that only one hardware engine in a group
[rcs0, ccs0-3] is active on a tile.

v2: - check CONFIG_DRM_XE_EUDEBUG and LR mode (Matthew)
    - disable preempt (Dominik)
    - lrc_create remove from engine init

v3: - remove redundant runalone setup (Sashiko)
v4: - deny if pxp is on (Sashiko)
    - deny if secondary mq (Sashiko)
    - deny if parallel (Sashiko)
    - really deny if pxp (Claude)

Assisted-by: Claude:claude-opus-5
Cc: Matthew Brost <matthew.brost@intel.com>
Signed-off-by: Dominik Grzegorzek <dominik.grzegorzek@intel.com>
Signed-off-by: Mika Kuoppala <mika.kuoppala@linux.intel.com>
---
 drivers/gpu/drm/xe/xe_exec_queue.c       | 63 +++++++++++++++++++++++-
 drivers/gpu/drm/xe/xe_exec_queue.h       |  2 +
 drivers/gpu/drm/xe/xe_exec_queue_types.h |  7 +++
 include/uapi/drm/xe_drm.h                |  2 +
 4 files changed, 73 insertions(+), 1 deletion(-)

diff --git a/drivers/gpu/drm/xe/xe_exec_queue.c b/drivers/gpu/drm/xe/xe_exec_queue.c
index a663c55b386d..d13f69eb025c 100644
--- a/drivers/gpu/drm/xe/xe_exec_queue.c
+++ b/drivers/gpu/drm/xe/xe_exec_queue.c
@@ -358,6 +358,9 @@ static int __xe_exec_queue_init(struct xe_exec_queue *q, u32 exec_queue_flags)
 	if (q->flags & EXEC_QUEUE_FLAG_DISABLE_STATE_CACHE_PERF_FIX)
 		flags |= XE_LRC_DISABLE_STATE_CACHE_PERF_FIX;
 
+	if (q->eudebug_flags & EXEC_QUEUE_EUDEBUG_FLAG_ENABLE)
+		flags |= XE_LRC_CREATE_RUNALONE;
+
 	err = q->ops->init(q);
 	if (err)
 		return err;
@@ -991,6 +994,51 @@ static int exec_queue_set_state_cache_perf_fix(struct xe_device *xe, struct xe_e
 	return 0;
 }
 
+static int exec_queue_set_eudebug(struct xe_device *xe, struct xe_exec_queue *q,
+				  u64 value)
+{
+	const u64 known_flags = DRM_XE_EXEC_QUEUE_EUDEBUG_FLAG_ENABLE;
+
+	if (XE_IOCTL_DBG(xe, (q->class != XE_ENGINE_CLASS_RENDER &&
+			      q->class != XE_ENGINE_CLASS_COMPUTE)))
+		return -EINVAL;
+
+	if (XE_IOCTL_DBG(xe, (value & ~known_flags)))
+		return -EINVAL;
+
+	if (XE_IOCTL_DBG(xe, !IS_ENABLED(CONFIG_DRM_XE_EUDEBUG)))
+		return -EOPNOTSUPP;
+
+	if (XE_IOCTL_DBG(xe, !xe_exec_queue_is_lr(q)))
+		return -EINVAL;
+
+	if (XE_IOCTL_DBG(xe, xe_exec_queue_is_parallel(q)))
+		return -EINVAL;
+
+	if (XE_IOCTL_DBG(xe,
+			 !(value & DRM_XE_EXEC_QUEUE_EUDEBUG_FLAG_ENABLE)))
+		return -EINVAL;
+
+	if (XE_IOCTL_DBG(xe, !xe_eudebug_is_enabled(xe)))
+		return -EPERM;
+
+	if (XE_IOCTL_DBG(xe, xe_exec_queue_uses_pxp(q)))
+		return -EPERM;
+
+	if (XE_IOCTL_DBG(xe, xe_exec_queue_is_multi_queue_secondary(q)))
+		return -EINVAL;
+
+	q->eudebug_flags = EXEC_QUEUE_EUDEBUG_FLAG_ENABLE;
+	q->sched_props.preempt_timeout_us = 0;
+
+	return 0;
+}
+
+int xe_exec_queue_is_debuggable(struct xe_exec_queue *q)
+{
+	return q->eudebug_flags & EXEC_QUEUE_EUDEBUG_FLAG_ENABLE;
+}
+
 typedef int (*xe_exec_queue_set_property_fn)(struct xe_device *xe,
 					     struct xe_exec_queue *q,
 					     u64 value);
@@ -1005,6 +1053,7 @@ static const xe_exec_queue_set_property_fn exec_queue_set_property_funcs[] = {
 							exec_queue_set_multi_queue_priority,
 	[DRM_XE_EXEC_QUEUE_SET_DISABLE_STATE_CACHE_PERF_FIX] =
 							exec_queue_set_state_cache_perf_fix,
+	[DRM_XE_EXEC_QUEUE_SET_PROPERTY_EUDEBUG] = exec_queue_set_eudebug,
 };
 
 /**
@@ -1077,6 +1126,17 @@ static int exec_queue_user_ext_check(struct xe_exec_queue *q, u64 properties)
 			 (properties & BIT_ULL(DRM_XE_EXEC_QUEUE_SET_PROPERTY_PXP_TYPE))))
 		return -EINVAL;
 
+	/*
+	 * A debugger can inspect and modify the EU state and memory of a
+	 * debuggable queue, so it must not be combined with protected content.
+	 * Test the property mask rather than the queue state, as the extensions
+	 * are applied in the order userspace chained them and either one may be
+	 * processed first.
+	 */
+	if (XE_IOCTL_DBG(xe, (properties & BIT_ULL(DRM_XE_EXEC_QUEUE_SET_PROPERTY_EUDEBUG)) &&
+			 (properties & BIT_ULL(DRM_XE_EXEC_QUEUE_SET_PROPERTY_PXP_TYPE))))
+		return -EINVAL;
+
 	return 0;
 }
 
@@ -1112,7 +1172,8 @@ static int exec_queue_user_ext_set_property(struct xe_device *xe,
 			 ext.property != DRM_XE_EXEC_QUEUE_SET_HANG_REPLAY_STATE &&
 			 ext.property != DRM_XE_EXEC_QUEUE_SET_PROPERTY_MULTI_GROUP &&
 			 ext.property != DRM_XE_EXEC_QUEUE_SET_PROPERTY_MULTI_QUEUE_PRIORITY &&
-			 ext.property != DRM_XE_EXEC_QUEUE_SET_DISABLE_STATE_CACHE_PERF_FIX))
+			 ext.property != DRM_XE_EXEC_QUEUE_SET_DISABLE_STATE_CACHE_PERF_FIX &&
+			 ext.property != DRM_XE_EXEC_QUEUE_SET_PROPERTY_EUDEBUG))
 		return -EINVAL;
 
 	idx = array_index_nospec(ext.property, ARRAY_SIZE(exec_queue_set_property_funcs));
diff --git a/drivers/gpu/drm/xe/xe_exec_queue.h b/drivers/gpu/drm/xe/xe_exec_queue.h
index 0225426c57b0..fb090704dd9f 100644
--- a/drivers/gpu/drm/xe/xe_exec_queue.h
+++ b/drivers/gpu/drm/xe/xe_exec_queue.h
@@ -162,4 +162,6 @@ int xe_exec_queue_contexts_hwsp_rebase(struct xe_exec_queue *q, void *scratch);
 struct xe_lrc *xe_exec_queue_lrc(struct xe_exec_queue *q);
 struct xe_lrc *xe_exec_queue_get_lrc(struct xe_exec_queue *q, u16 idx);
 
+int xe_exec_queue_is_debuggable(struct xe_exec_queue *q);
+
 #endif
diff --git a/drivers/gpu/drm/xe/xe_exec_queue_types.h b/drivers/gpu/drm/xe/xe_exec_queue_types.h
index 95f75d61a647..67c4c974d13d 100644
--- a/drivers/gpu/drm/xe/xe_exec_queue_types.h
+++ b/drivers/gpu/drm/xe/xe_exec_queue_types.h
@@ -154,6 +154,13 @@ struct xe_exec_queue {
 	 */
 	unsigned long flags;
 
+	/**
+	 * @eudebug_flags: immutable eudebug flags for this exec queue.
+	 * Set up with DRM_XE_EXEC_QUEUE_SET_PROPERTY_EUDEBUG.
+	 */
+#define EXEC_QUEUE_EUDEBUG_FLAG_ENABLE		BIT(0)
+	unsigned long eudebug_flags;
+
 	union {
 		/** @multi_gt_list: list head for VM bind engines if multi-GT */
 		struct list_head multi_gt_list;
diff --git a/include/uapi/drm/xe_drm.h b/include/uapi/drm/xe_drm.h
index 03cb1181c169..a938a9f095ce 100644
--- a/include/uapi/drm/xe_drm.h
+++ b/include/uapi/drm/xe_drm.h
@@ -1442,6 +1442,8 @@ struct drm_xe_exec_queue_create {
 #define     DRM_XE_MULTI_GROUP_CREATE				(1ull << 63)
 #define   DRM_XE_EXEC_QUEUE_SET_PROPERTY_MULTI_QUEUE_PRIORITY	5
 #define   DRM_XE_EXEC_QUEUE_SET_DISABLE_STATE_CACHE_PERF_FIX	6
+#define   DRM_XE_EXEC_QUEUE_SET_PROPERTY_EUDEBUG		7
+#define     DRM_XE_EXEC_QUEUE_EUDEBUG_FLAG_ENABLE		(1 << 0)
 	/** @extensions: Pointer to the first extension struct, if any */
 	__u64 extensions;
 
-- 
2.53.0